Battery-powered electronic devices, electronic devices that derive some or all of their operating power from one or more batteries, are popular, widely available and in relatively widespread use. In particular, electronic devices that use batteries as a primary operational power source are able to be portable and mobile, such that the devices are effectively free from a fixed location and power source. In many instances, portability is responsible for much of the market share attributed to such devices. Examples of popular battery-powered electronic devices include, but are not limited to, notebook and laptop computers, hand-held computers and personal digital assistants (PDAs), digital cameras, and cellular telephones.
Given that many battery-powered devices depend on batteries as a primary power source, most battery-powered electronic devices closely monitor a charge level remaining in the batteries in order to insure reliable operation of the device. Among other things, remaining charge is used to determine a cut-off point for the batteries at which the device automatically initiates a ‘soft’ shutdown. Automatic soft shutdown helps to insure data integrity and operational reliability when batteries near an end of useful charge. In addition, remaining charge level is also often employed by the electronic device to give a user of the device an indication of how much operational time may be available as well as warn the user of an impending or potential loss of operational power.
Inaccuracies in battery charge level monitoring, as well as a need to insure that shutdown occurs before the normal operation of a device is affected by loss of sufficient battery power, often lead to an effectively artificial reduction in the apparent charge life of a given set of batteries. Specifically, monitoring that determines a charge level of the battery to be lower than it actually is can result in a shutdown occurring sooner than it should. In addition, to insure normal operation of the device under all operating modes, the battery cut-off point is generally set conservatively based on a power requirement of an operational mode with a highest power utilization. In short, both the monitoring inaccuracies and the use of a conservative cut-off point typically result in an unnecessarily premature indication of effective end-of-charge life in many battery powered electronic devices.
Thus, it would be advantageous to be able to potentially extend a useable lifetime of a battery by improving battery charge level monitoring accuracy as well as reducing the need for unnecessarily conservative cut-off points for batteries used in battery-powered electronic devices. Such an improved monitoring accuracy and cut-off determination may extend the useful life of batteries in battery-powered electronic devices thus solving a long-standing need in the area of battery-powered devices.